A suicide attacker on foot blew himself up near a compound belonging to the Afghan intelligence agency in Kabul on Monday, killing six civilians, officials said.
The attacker struck at a time when workers were arriving at their offices. It comes a week after militants stormed a National Directorate of Security (NDS) training centre in the Afghan capital.
Interior ministry spokesman Najib Danish told AFP six civilians in a car were killed when the attacker detonated himself.
"Six people were martyred and three others were wounded," Danish said.
"They were hit when they were passing the area in their Toyota sedan vehicle. We still do not know the target of the attack but it happened on the main road."
An AFP reporter at the blast site said the attack happened outside the main entrance to an NDS compound. Security forces have swarmed the area, closing off the main road leading to the building.
"Our initial information shows a blast took place near an intelligence headquarters in Shash Darak neighbourhood of Kabul," deputy interior ministry spokesman Nasrat Rahimi told AFP.